// Recursively decompose phis for each field.
	for _, f := range fields[:n] {
		decomposeUserPhi(f)
	}
}

// decomposeArrayPhi replaces phi-of-array with arraymake(phi-of-array-element),
// and then recursively decomposes the element phi.
func decomposeArrayPhi(v *Value) {
	t := v.Type
	if t.NumElem() == 0 {
		v.reset(OpArrayMake0)
		return
	}
	if t.NumElem() != 1 {